JS Numbers

Overview

Numbers in JavaScript are used to represent both integer and floating-point values. They are fundamental for performing mathematical operations, storing numeric data, and making calculations in programs.

Creating Numbers

Numbers can be assigned directly to variables

Try yourself 
        
            let integerNumber = 42;
let floatingPointNumber = 3.14;

console.log(integerNumber)    // 42
console.log(floatingPointNumber)   // 3.14

Basic Arithmetic Operations

JavaScript supports standard arithmetic operations like addition, subtraction, multiplication, and division.

Try yourself 
        
            let sum = 10 + 20;          // 30
let difference = 50 - 30;   // 20
let product = 5 * 6;        // 30
let quotient = 15 / 3;      // 5

console.log(sum)        // 30
console.log(difference) // 20
console.log(product)    // 30
console.log(quotient)   // 5

Math Object

JavaScript's Math object provides a range of mathematical functions and constants

Try yourself 
        
            let pi = Math.PI;                // 3.141592653589793
let squareRoot = Math.sqrt(16);  // 4
let random = Math.random();      // A random number between 0 and 1

console.log(pi)         // 3.141592653589793
console.log(squareRoot) // 4
console.log(random)     // A random number between 0 and 1

Rounding and Truncation

JavaScript provides methods for rounding numbers

Try yourself 
        
            let rounded = Math.round(4.5);     // 5
let floorValue = Math.floor(4.9);  // 4
let ceilValue = Math.ceil(4.1);    // 5

console.log(rounded)      // 5
console.log(floorValue)   // 4
console.log(ceilValue)    // 5

Number Precision

JavaScript uses 64-bit floating-point representation, which can result in precision issues for very large or very small numbers. Libraries like BigInt and Decimal.js can help manage precision.

NaN and Infinity

JavaScript has special values for calculations that can't produce a valid result

Try yourself 
        
            let result = 0 / 0;      // NaN
let positiveInfinity = 1 / 0;  // Infinity
let negativeInfinity = -1 / 0; // -Infinity

console.log(result)             // NaN
console.log(positiveInfinity)   // Infinity
console.log(negativeInfinity)   // -Infinity

Number Methods

JavaScript provides several methods for working with numbers

Try yourself 
        
            let number = 42.34567;
let numberAsString = number.toString();         // "42.34567"
let fixedNumber = number.toFixed(2);            // "42.35"
let precisionNumber = number.toPrecision(4);    // "42.35"
let parsedInt = parseInt("42");                 // 42
let parsedFloat = parseFloat("42.34567");       // 42.34567

console.log(number)           // 42.34567
console.log(numberAsString)   // "42.34567"
console.log(fixedNumber)      // "42.35"
console.log(precisionNumber)  // "42.35"
console.log(parsedInt)        // 42
console.log(parsedFloat)      // 42.34567

Summary

Numbers in JavaScript are fundamental for mathematical operations and calculations. JavaScript provides various methods and functions for working with numbers, including arithmetic operations, mathematical constants, rounding, and precision management.